PUPILS walked out of classrooms in protest against Big Brother-styled CCTV cameras recording their lessons.
They were so angry with the installation of the equipment at Davenant Foundation School in Chester Road, Loughton, they refused to return until they received assurances it had been turned off.
It meant they missed three weeks of studies and led to the drafting of a petition signed by about 150 of their peers.
And when they did return to the classroom they all wore masks to continue their protest.
The school, an accredited teacher training centre, said the equipment has been installed in two classrooms to capture footage showing examples of best practice in the profession, and would not be used without pupils' knowledge.
The issue has now been reported to UK privacy watchdog, the Information Commissioner's Office (IOC), which is due to clarify the guidelines by the end of the month.
A father, whose son took part in the walk-out, said the school was wrong not to consult parents about the use of technology which "threatened our children's civil liberties".
He said: "There is a sphere-like camera at the front and two more cameras at the back. My son said he found it quite intimidating."
The school, a mixed comprehensive which takes pupils from across Essex and east London, has previously drawn criticism from parents for introducing a finger-scan recognition scheme in its canteen to allow pupils to buy lunch.
But headteacher Chris Seward says the new technology would only serve to drive up standards at the school, which is consistently one of the best performers in the county.
He said: "There was a small group of sixth-form students who protested because they felt these cameras would be used to film all their lessons. I also had some written representations from parents and I addressed their concerns in our newsletter. They took it all very seriously and I respect that.
"But once we spoke to them to explain the cameras would be used for a specific purpose they returned to class. Now we are waiting for the Information Commissioner to approve the guidelines and protocols before we can start using the cameras."
Epping Forest MP Eleanor Laing, who has written to the school on behalf of concerned parents, and is due to meet the Information Commissioner to discuss the case, said: "We need to find out if the pupils are happy to be filmed but there are two valid sides to this argument, and I am trying to get to the bottom of it.”